CIRCULATION, BLOOD AXD GLANI»> ±2;^
remains open till the milk dentition is complete in ^:^^; of the Aioes, but more investigation is necessarv to settle
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this point. The ligamentam arteric^m is thick in the adult Gorilla \Eisler •.
The pulmonary artery is as in Man, but is relatively wider in the Chimpanzee. It divides as in Man. Eisler (442j describes its relations to the bronchi in the as being similar to those in Man.
i-crt?N of ins Head and Xcc*:.
The common carotid arteries divide internal and large external carotid arteries at the upper border of the thyroid cartilage. In many Apes it gives off branches to the thyroid gland when there is no thvroid branch of the subclavian arterv. The following
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table shows some of the arrangements : —
Mar Gcr".i!a> Ci:i::;par: e^
No branches .. (1) Inferior thyroid (1) As in man i442>.. No branches
branch (442 (*2) Inferior thyroid
Superior and branch »399) nfenor thyroid , (3) Middle and inferior branches thyroid arteries ^399«
The external carotid artery (fig. 42) has the same course and relations as In Man, but the branches are fewer in the Apes. There is a linguo-facial artery which breaks up into lingual and facial arteries; and the occipital and posterior auricular arteries arise from an occipito-auricular trunk in the Gorilla and Chimpanzee, but these vessels arise separately in the Orang. In the Gorilla alone there is an ascending palatine artery in addition to the ascending pharyngeal vessel. The